


The Experiment

by twobit22



Category: Sonic the Hedgehog (Video Games)
Genre: M/M, NSFW, Other, Sex, Smut, mature - Freeform
Language: English
Status: Completed
Published: 2013-11-09
Updated: 2013-11-09
Packaged: 2017-12-31 22:37:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,027
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1037189
Author URL: https://archiveofourown.org/users/twobit22/pseuds/twobit22
Summary: <blockquote class="userstuff">
              <p>Finding it better to work on his own plans, Metal Sonic has ventured off to live on his own. However, during his latest research, he starts growing curious about a new kind of experiment with a frequent visitor.</p>
            </blockquote>





	The Experiment

**Author's Note:**

> This work contains explicit sexual-content. This is NSFW and those not wanting to see should turn away now. Thank you.

Metal continued to tap his foot impatiently as he waited for his usual guest. First he scolds him for arriving too early for his appointments, but now he was late? The robot huffed as he crossed his arms, and decided to reprocess the data he had downloaded earlier. Ever since Shadow's recent visits, he had grown curious as to the very nature of organic rituals and their display of affections toward one another. The other hedgehog seemed to act in a similar matter, even if his words contradicted it.  
  
Metal shook his head as he came across another set of valuable, but embarrassing bits of information. He would rather avoid the need for those kinds of experiments if he could help it.  
  
“Alone again? Am I really the only one you invite over?” Shadow questioned.  
  
Metal's optics were shinning brighter than usual as he tried to hold himself back from lashing out at Shadow. How it infuriated him that the other could manage to sneak around like that. The fuming robot was starting to wonder if his systems were really slowing down.  
  
“What did I tell you about sneaking around?! One of these days, my response time might be delayed and you will end up mangled.”  
  
The grumpy robot sighed before pushing a door open to the work room while making his way through. Thanks to Shadow's tardiness, he wanted this over with as quickly as possible.  
  
There was a very large steel reinforced work table in the middle of the room. Pipes and wires were worked around the many bars being used to hold up the flatter surface. Metal waited as Shadow laid down along one side of the table before getting the overhead scanners ready.  
  
“I'm beginning to wonder about this work of yours. One scan should have been enough.” Shadow scoffed.  
  
“I want to see if I can get more data from the equipment since my internal scanners seem to have limitations.”  
  
Metal tapped a few more keys on the computer before laying down on the other side of he table himself. They both waited a moment before a long white scanner appeared from the end of the table and was raised high enough to not hit either of them as it moved up and down the table. Metal glanced in the corner of his optics and noticed Shadow seemingly more relaxed than usual. He seemed to be more accepting of the procedures as the days went by.  
  
Once the scans had finished, Metal melted down into liquid form for a few moments before coming back in a very similar body from his last. Cosmetic wise, his turbine was smaller and his parts seemed sleeker than usual. His muzzle was even defined to a point to include a mouth, but one may not notice at first glance. The real change, however, were the several modifications to his engine and sensors.  
  
“So this is how you are able to make upgrades on your own. Is it permanent?” Shadow asked.  
  
“Nothing is permanent. As long as I have the data on file, I can continue to change at will. However, this is still within the prototype stage.”

Metal pulled himself up before resting on his knees. Flexing his hand for a moment, the robot took in the sensations of the tips of his fingers touching the palm of his hand. Peculiar was the only word that could come to mind.

“With this new data, I am now able to make a proper update to my body sensors. When needed, I can make them just as sensitive as an organics. Perhaps even more so.” Metal stated.  
  
He stopped as the sensors in his back could feel the tips of fur coming from the looming hedgehog behind him. What Metal hadn't calculated was a small delay in his reaction time while he was processing the new information. Shadow had wrapped his arms around the robot's waist before pulling him closer.

  
“What are you doing?!”  
  
“Maybe these sensors need a proper testing. Let me help you experiment.” Shadow whispered.  
  
Metal flinched as he felt eager hands roaming up and down his sides. The 'bot reached his hand up as to motion him away, when he stopped to take in a new sensation. He could 'feel' static rushing along the sensors as Shadow's fur rubbed up closer against him. The overwhelming feeling caused the robot to arch his back, and let out a startled gasp. So it seemed with the additional data, he could also mimic various sounds?  
  
“Maybe we should save this for another time?” Shadow offered before moving his hands away.  
  
Metal wasn't sure what just happened. Had he made the other hedgehog nervous already? He could feel error messages flooding his systems as he debated through the two logical options presented to him. Normally he would not allow anyone to lay a finger on him, but this wasn't just anyone. The moment he realized this, a new set of commands unlocked themselves as well as possibilities that had been learned of from his latest 'research.' Did Shadow really wish to show this form of affection towards him?  
  
“Er—No. Continue...” Metal's speakers seem to shudder.  
  
Shadow didn't waste any time as his moist tongue could be felt licking along the side of the machine's neck. Metal let out light moans as his body shivered from the touch. The lighting in his optics pulsed in confusion when he noticed Shadow biting at the tip of his gloves before removing them. The darker hedgehog only grinned as his hands gently traced along the edges of the metallic plating. Metal let out a pleasurable moan as he felt Shadow fingers along the edges of his engine intake.  
  
Shadow chuckled as he focused more attention along the 'bot's rims. For someone that was normally so rough, he was very gentle to the touch. Metal let the new commands take over as his body began to warm up along the sensors. He shivered and squirmed as he felt Shadow buck his hips up against his backside, causing short burst of static to rush through his wiring. The robot had never felt bliss quite like this as he eagerly rocked his backside in rhythm with his partner. 

Metal slowed down when he felt another rush of energy flowing through him. It felt as though Shadow was emitting small burst of chaos energy against his rims. As the darker hedgehog moved his hands down to the robot's waist, he increased the speed at which is hands would rub along his sleek frame. The moaning 'bot reeled his head back while chaos energy was creating a build up deep within his main engine. He was unsure how much longer his body would be able to keep up.  
  
“Shad--I can't--” Metal stuttered.  
  
The stuttering robot had nearly lost all control of his voice box as well as loosing the function to keep his body upright. He leaned his frame up against his guest as he continued to cry out from the overwhelming pressure inside. The robot shook his head between whimpers as he felt Shadow's hands roam along his body. Each touch felt like it was emitting more energy than the last.  
  
Static and jumbled error messages covered his field of vision as the sensors started to overload. Right as the robot felt the need to 'release' the overflowing energy, his organic partner grabbed a small cable plugged into a nearby computer before connecting it to one of Metal's ports. The 'bot let out a cry as the majority of main engine's energy released its energy into the larger computer.  
  
Metal collapsed into Shadow's arms as his optics dimmed, and his body went into a temporary stand-by mode. He waited as the energy gradually transferred itself and brought his systems back to default settings. Although Metal appeared offline, he was still very much aware of his surroundings. He  watched as the panicking hedgehog held the robot close in his arms and called out for a response. If Shadow was aiming to 'tease' him like this, it was only fitting if he returned the favor.

 

Metal's optics shined once more before he turned to push the worried hedgehog down against the table. The startled guest had little time to react as Metal held both of his arms down, and a pair of metallic bands on either end of the table locked the organic's wrists into place. Shadow's voice seemed tense as stared up at the grinning robot above him.  
  
“W-what are you doing?!”  
  
The ebony hedgehog's ears folded back as Metal let out a chuckle before leaning down to lick along Shadow's collarbone, and slowly worked his way to his shoulder. He let his metallic claws comb through the organic's chest fur as static was building between his fingers. The sensation was driving him wild with anticipation.  
  
The darker hedgehog squirmed as he felt Metal nuzzling and licking along his neck. He let out a hiss of pain as the tips of Metal's steel fangs lightly grazed along the side of his neck. Small drips of blood leaked from his wound before being hastily licked up. Shadow clenched his fists and shivered from the peculiar actions coming from his robotic companion. Metal moved his head up until he was only inches away from the worried hedgehog's face.   
  
“Did you really think I would let you get away with having all the fun? This is my experiment, remember? Now, the real question is, are you willing to see this through?” Metal whispered before tracing the tip of his tongue along Shadow's lips.  
  
Shadow's scowl had softened as he looked back up at Metal. The robot could feel the organic's legs wrap around his waist as he pulled him closer before tilting his head to kiss along the robot's chrome muzzle. The 'bot froze for a moment, unable to understand how he could still act so confident about himself even in this position.  
  
“Heh, I'll play your little game. If you think you can outlast me, then bring it,” Shadow purred.  
  
Shadow had taken advantage of his partner's slowed movements as he bucked his hips and attempted to force the robot closer to his level. His lips were pressed hard against Metal's muzzle as he manged to wrestle the robot's tongue into his kiss. The bewildered bot grunted as he broke himself from his daze and attempted to fight back. The robot's motor made it sound like he was purring as he began to gently grind back against his partner.  
  
The aroused 'bot knew the hedgehog was pleased with this actions as he could feel the organic bucking his hips harder against his motions. Shadow gasped in delight before Metal dove his tongue further inside to take control of the kiss. Finally as their muzzles parted, the robot traced the tip of his fangs along the other hedgehog's lips. Despite the minor bite, Shadow was struggling to push himself closer but to no avail.  
  
“You're getting ahead of yourself.” Metal moaned before lifting himself upright.  
  
He began to trail both hands across Shadow's chest while admiring the full view of the figure below him. The ultimate lifeform had always been easy on the optics, but being able to finally feel him was more than the robot could have ever hoped for. Despite his slender appearance, beneath that thin layer of fur were sets of thinly lined muscles all down his chest and upper abdomen. It was nothing noticeable, but a reminder of there being more to Shadow than his softer appearance.  
  
The thrill of this danger caused Metal's metallic parts to heat up as his hips rocked slowly against the moaning hedgehog. He tilted his head curiously as he noticed Shadow's feature finally revealing itself. He traced one hand along Shadow's inner thigh while using the other to hold his leg apart. The excited guest gasped as these advanced caused his member to harden.  
  
“This is going by faster than I had calculated. If I didn't know any better, you were waiting for this long before we started?” Metal chuckled.  
  
The laughing robot regretted his comment as he noticed Shadow turn his head away in frustration. Maybe his guest was more nervous about the situation than he let on? Metal waited a moment, admiring the ultimate lifeform's 'size' before leaning in for a closer look.  
  
Metal purred as his cold metallic tongue began to stroke along the underside of Shadow's member. The darker hedgehog struggled to hold back a husky groan as his member twitched to the touch. His tongue would partially wrap around the hedgehog's member as artificial saliva dripped from his mouth. As he worked his way to the tip, he gave the shivering member several light licks as he tasted the leaking the stimulation had caused.   
  
As his mouth moved in a little closer, he noticed Shadow's face looking down at him expectantly and very flushed. It took him a moment to retrieve the data from his previous research before he had an idea of what Shadow had been wanting. Metal only grinned before shaking his head.  
  
“You would like that wouldn't you? But I don't think this upgrade is ready for that kind of act. However, there is something else I can do for you...”  
  
Metal started to trail off before gently wrapping his metallic fingers around Shadow's shaft and began pumping him slowly. He smiled as Shadow's efforts to hold back were proving too difficult and moans escaped from the squirming hedgehog under him.  
  
“Just awhile ago you were more than eager to play this little game. Why the hesitation now?”  
  
“Heh, did you think it would be that easy? You'll have to work me harder than that.” Shadow panted.  
  
“Be careful what you ask for.”  
  
Metal had not been at all convinced by Shadow's words. He was trying to be stubborn as always. Metal placed his other hand over Shadow's member as clear liquid shot from the tips of his finger and dripped along the length. The ebony hedgehog's eyes widened in confusion and his member shivered to the touch.  
  
Metal slowly glided his hand from the shaft and along the length of his member as Shadow let out a low groan of approval. The frustrated bot was far from pleased with this outcome as he needed a better reaction out of his guest than this. He wanted to make Shadow feel even more overwhelmed than what had been done to himself.   
  
He carefully placed two fingers inside Shadow's backside before releasing streams of lubricant from the tips of his fingers. Shadow let out a light hiss of pain and his member leaked slightly from the sudden intrusion. He waited until Shadow's initial resistance subsided before inching his fingers in deeper. Metal watched with curiosity as Shadow leaned his head back and grunted between gritted teeth.  
  
As Metal carefully used his fingers to spread the liquid through Shadow's backside, he was increasing the motions in his other hand as he pumped his partner's member. The panting hedgehog seemed to be enjoying the attention as he heard a moan escape Shadow's lips as well as his body loosening up. Metal would part his fingers from each other before pushing them deeper into Shadow. He was carefully exploring for a particular spot. His optics brightened as he felt Shadow tighten up and gasp once more.  
  
“R-right there!” Shadow panted.  
  
Metal nodded before picking up the pace with both hands. His two fingers would prod at the sensitive area in short quick bursts, only giving the other hedgehog mere seconds before feeling the sensation again. Metal could feel Shadow's member tense up as the darker hedgehog was struggling to keep his voice down. A very sly smile crossed Metal's face as he felt Shadow rocking his backside in rhythm with his own motions.  
  
The robot removed both hands from the moaning hedgehog and placed them at the edge of the table above his head. Out of all the organic desires his programming had observed, nothing could compare to this. For the first time, he wanted to know what it was like to belong and for another to be his. The one that made his sensors go wild just processing him. The eager bot started to prod at Shadow's backside with another feature from between his legs. He leaned in close before whispering into the organic's ear.  
  
“Seems to me like you were enjoying yourself. But...I think you just need one more push.”  
  
Metal's optics dimmed as he slowly slid the metallic tip of his member back and forth into needy hedgehog's area. Shadow let out a gasp and his back arched up in response to the sudden entry. The machine's body shivered as the position allowed him to press himself in further. However, it was starting to feel too tight. He reached down to pump at the organic member while gently rocking his hips into the distressed hedgehog.  
  
The ebony hedgehog's groans of pain were slowly turning to a more pleasurable sound as his body was finally accepting the intrusion. With each thrust, the robot would pull back as far as he could go before pushing himself deeper into his partner. He continued with a very steady rhythm so that the squirming hedgehog might take in every last sensation the ribbed member was giving him. Metal let out a gasp as Shadow's walls tensed and tugged around his sensitive extension.  
  
“Someone is eager for more I see,” Metal moaned.  
  
“Wh-what gave you that idea?!”  
  
“If you want to finish, you are going to have to beg for it. Now, how about this?”  
  
A very faint humming could be heard coming from Metal's member as it began to vibrate gently along his organic partner's walls. Shadow reeled his head back as he bucked his hips against the sensual massage he was being given. However, Metal wanted far more than just a little purr out of his test subject. He increased the speed at which he rocked his hips, still being careful not to rub against his sensitive spot just yet. The whimpering organic dug his nails into the table as his walls adjusted to the size of the metallic member. Even Metal was starting to feel apprehensive at this point.  
  
The needy bot lifted the darker hedgehog's legs above his shoulders before thrusting his member deeper inside. This time, as the ribbed portion of his vibrating feature rubbed against the organic's sweet spot, a panting cry escaped the hedgehog's lips. Metal increased the speed of his thrusting as he watched the squirming guest below him. Shadow struggled against the cuffs and feebly attempted to rock his hips. However, in this position, Metal had been given full control.  
  
The robot's optics glowed a deeper crimson as waves of pleasure flowed through his sensors and into his circuitry. He needed more. He didn't just want the feeling, but the pleasure knowing he could make the ultimate lifeform his. Metal shivered at the thought and began to lose his rhythm. His trance was quickly broken as he noticed left metal band holding Shadow down had been torn from the table.

 

The startled robot lowered his partner's legs before diving down to try and pin the other hedgehog. Metal froze as he felt the warm gently touch of his guest's hand against his muzzle. Shadow was laying there motionless, but smiling back up at his robotic partner as he pulled their muzzle's closer together.  
  
“You've got something on your mind? Tell me.” Shadow whispered while only inches away from his face.  
  
“I'm not sure. Something about you I—I need this!” Metal panicked.  
  
For a moment, Shadow stayed there completely silent. The nervous bot almost removed himself until he felt the darker hedgehog nuzzling against his muzzle. The robot whimpered as he nuzzled back, his previous commands seeming to escape him. He was terribly confused now. Did the organic wish to continue the ritual? Did he really desire him? Before he could question, he felt the darker hedgehog's legs wrap around his waist once more while rocking his backside against the still exposed metallic member.

“A-ah-I need this too. Now lets end this little game...” Shadow begged.  
  
“Shadow--?”  
  
“If you can't explain how you feel, then show me!”  
  
Little hesitation came from Metal's end as he thrust his member back into his partner. Shadow grunted between gritted teeth, but wrapped his legs even tighter around his metallic companion. The 'bot used one hand to support himself, while the other interlocked its fingers with the other hedgehog's free hand. Never in all his programming had he felt this close to being 'alive'? His sensors were starting to overload once more as he felt Shadow's walls warming up with each thrust.  
  
Metal could hear his partner begging for more as he was hesitant to comply. Could the organic handle this? He pushed his member in deeper while rubbing it against the sweet spot. Instead of long thrusts, he rocked his hips in very short bursts. His metallic member vibrating against the sensitive area over again with little break in between. The grunting bot reached and claws ran deep into the top edge of the table while using this new leverage to pump against his partner even faster. Shadow's panted cries echoed through the steel room and drove the robot's sensors to the edge. Metal leaned forward while stuttering a harsh whisper into his partner's ear.  
  
“Mine...”  
  
“M-Metal?!” Shadow trembled.  
  
His optics dimmed and body shuddered as he felt an even stronger pulse of pleasure flowing through his metallic interior. Metal tried to withhold the feeling and the longer he did, the more the sensation seemed to build. However, the moment had been broken almost as soon as it had began as Shadow's cry had far outweighed the robot's moans and his seed spilled across his chest. Synthetic fluid soon released into Shadow's backside as the bot shivered while removing himself. His energy seemed to be quickly draining.  
  
“Heh...looks like I won after all,”  
  
“S-stop being rubbing it in.” Shadow panted.  
  
Metal rolled over to his side of the table before his body converted itself to his original form. Soon, he would be without any energy. He struggled to pull himself off the table, but was finding it increasingly difficult to even lift his limbs. Even though the sensors in his normal form were weak, he could feel Shadow looming over him. The groaning hedgehog made a reach for the nearby hook ups while opening the panel on the robot's side.  
  
“Thank you. But it may take me a long time to recharge with this method.”  
  
“That's fine. Heh, I'm going to need a lot  of 'recharge time' myself,” Shadow joked  
  
Metal's body jumped as he felt jolts of electrical current rushing through his frame. One by one, different sets of his body were slowly being triggered into stand-by mode. However, not before he felt his organic partner wrap an arm around his waist.  
  
“Shadow...you were always my favorite guest.” the weary bot murmured.  
  
“What are you talking about? I'm your only guest.”  
  
“Yes, but then why do you never stay?”  
  
“Is that what you were asking earlier?”  
  
Metal's optics shifted from one side to the next nervously as he took hold of Shadow's hand. He really hoped the organic hadn't heard that.   
  
“Are these test proving too difficult for you to handle? Maybe I should--.”  
  
Metal was cut off as he felt Shadow's grasp tighten. The organic seemed to be purring against his ear now, causing the robot's frame to shiver. His optics brightened as he hadn't expected the next response.  
  
“It's fine. Why else do you think I keep coming back?”  
  
"I-I see. Well then, you're not going to mind if I plan for a few follow-up sessions?"  
  
"Heh, I'm looking forward to it."  
  
It was still a little early for Metal to decide if keeping the other hedgehog around was wise or not. However, he was already looking forward to the idea of having company. His optics dimmed as he slowly felt his sleep mode taking effect.


End file.
